1. Field of the Invention
The present invention relates to an incremental or absolute rotation encoder with a clamping device for connecting the encoder shaft to the drive shaft of a drive unit by means of a radial clamping action.
2. Description of the Prior Art
Incremental or absolute rotation encoders of this type are used particularly in processing machines for measuring the relative position of a tool relative to a workpiece to be worked on.
German Pat. No. 3,427,709 describes a rotation encoder with a clamping device for connecting the encoder shaft to the drive shaft of a drive unit. In this encoder, the encoder shaft is constructed as a tubular shaft which, at its end to be connected to the drive shaft, has a conical inner portion which defines a plurality of axial slots. This end of the encoder shaft with the conical portion engages in a coaxial bore of a connecting element which is fixedly coupled to the drive shaft of the drive unit. A pressing screw is inserted into the hollow encoder shaft from the rear side of the encoder. The pressing screw acts to spread apart the conical portion of the encoder shaft for effecting a frictional engagement of the encoder shaft with the connecting element. However, the hollow encoder shaft with the inner conical portion and the axial longitudinal slots is difficult to manufacture.
It is, therefore, the primary object of the present invention to provide a rotation encoder with a clamping device of simple construction for connecting the encoder shaft to the drive shaft of a drive unit.